Origin of land plants using the multispecies coalescent model

• Zygnematales as the closest lineages of land plants is the best hypothesis using phylogenomic data and the coalescent model, and other alternative relationships suggested by previous studies are rejected by a likelihood ratio test.
• The coalescent model can accommodate gene tree heterogeneity in deep-level phylogenies regarding the origin of land plants.

The origin of land plants is a fundamental topic in plant evolutionary biology. Despite the crucial importance for knowing the closest lineages of land plants, this question has not been fully answered yet. Using recently available nuclear sequences from streptophyte algae, the multispecies coalescent model produces a congruent phylogeny that is robust to different data sets, in contrast to the conflicting phylogenies produced by the concatenation method. Using phylogenomic data and the coalescent model, in this opinion article we postulate that the Zygnematales are the closest lineages of land plants. We suggest that the coalescent model can accommodate gene tree heterogeneity in deep-level phylogenies and can be potentially used to resolve other deep species phylogenies.